Let it not be said that hip new music is light new music. Ethel, a contemporary string quartet variously heralded as “funky,” “downtown” or, worst, “postclassical,” came to the District on Monday night with a new program of three long works about the Balkan conflict, the attacks of Sept. 11, 2001, and the Holocaust: almost two hours of music with no intermission. While the quartet sounded terrific and the music was staggering, the cumulative effect was as bludgeoning as such heavy adjectives indicate. Steve Reich’s “Different Trains” is one of the best pieces in the contemporary canon, but by the time we got there, it was hard to feel anything but worn down by all of the passionate intensity.

Ethel arrived courtesy of the Atlas’s new new-music series, which looks to be one of the new year’s happiest developments on the Washington music scene. Curated by Armando Bayolo, founder of the Great Noise Ensemble, it’s bringing a panoply of important musicians, such as pianist Kathleen Supove (who is performing one of her “Exploding Piano” events here on Feb. 7) or Ethel, with its rock-band vibe and its focus on music written since the mid-1990s.

In its 14th season, Ethel is a middle-age hipster in quartet years, anchored by only two of its founding members, violist Ralph Farris and cellist Dorothy Lawson, who on Monday sat flanking the two junior-member violinists, Jennifer Choi and Cornelius Dufallo, as if establishing rank — or reining in two crack soloists who in any case tended to dominate. The real tone was set when Choi opened the first piece, Aleksandra Vrebalov’s “ . . . hold me, neighbor, in this storm . . . ” with the querulous tones of a gusle, a long-necked stringed instrument that’s a staple folk instrument of the Balkans, while Dufallo struck doleful, melodious thwunks from a tuned drum standing in for the traditional tapan.

With taped church bells, muezzin calls and the half-tuned folk singing of an old woman augmented by foot-stomping and vocal exclamations from the performers, “ . . . hold me” created an evocative sound world, now elegaic, now folksy, with a kind of sepia intensity: a veritable musical documentary that managed to hold its own with the two other contemporary classics. By contrast, John King’s powerful “AllSteel” is a response to rather than an illustration of 9/11. Four of its movements — muscular and driving and energized — were begun on Sept. 10, 2001. After Sept. 11, King reconceived the piece by answering each with a quiet meditation, harmonics such as smoke drifting up from the ruins. The result amounts to two antiphonally interleaving quartets, crystallizing around a cadenza-like passage for solo violin in which Choi tried to fiddle her way out of solitude as the other players began to chime in, then again fell silent.

Ethel sounded robust in its current incarnation, but playing so much hard and wrenching music took a toll. “Different Trains,” an autobiographical account of Reich’s long train journeys as a child in the early 1940s juxtaposed with the train journeys that other young Jewish children were taking in Europe at the same time, was certainly the crowning work of the evening, but hints of imprecision in the performance suggested that it wasn’t only the audience’s attention that was flagging. Reich created a collage of taped speech from Pullman porters, his nanny and Holocaust survivors, turning them into fragments whose speech-song is picked up and amplified by the strings, establishing a kind of documentary music that was a precursor to Vrebalov’s later piece. It’s a gorgeous work and deserves to be savored. Intermission small talk might seem sacrilegious in the face of as much anguish as this program represents, but the power of the music might have been even clearer after 10 minutes of silence.

Ethel’s players are, from left, Ralph Farris, Dorothy Lawson, Jennifer Choi and Cornelius Dufallo. (James Ewing)